Laser power is a key factor in determining the microstructure and properties of metal materials prepared by additive manufacturing. This study selected the optimal laser power to enhance the corrosion resistance of maraging steel fabricated by direct energy deposition (DED). When the laser power was 3500 W, the corrosion current of the maraging steel was the lowest and the charge transfer resistance was the highest, demonstrating the best corrosion resistance. This is because at this laser power, the density of the maraging steel was the highest, reducing the penetration and diffusion of corrosive media. In addition, the content of high-valent Ni and Cr elements on the surface of the 3500 W maraging steel was higher than that of samples under other laser powers, indicating that the passivation film on its surface was denser than that of other samples, thereby slowing down the corrosion rate. This study proves that by adjusting the laser power, the density of the material and the composition of the surface passivation film can be precisely controlled, providing theoretical and experimental guidance for improving the corrosion resistance of maraging steel fabricated by DED.
Zhang et al. (Sun,) studied this question.